PALM BEACH, Fla. -- The Palm Beach police chief said yesterday he was "99 percent sure" that a sexual crime took place at the Kennedy compound over the Easter holiday weekend.

"Something could jump out at us that we're not aware of and change that assumption," Chief Joseph Terlizzese said. However, he added: "At this point it looks like we have reasonable suspicion that a crime was committed."

The chief's comments were his first assessment on the strength of a rape report from the Kennedy compound March 30. Police say William Kennedy Smith, 30, a nephew of Sen. Edward Kennedy, D-Mass., is the suspect in the case.

A 29-year-old Jupiter, Fla., woman told police that Mr. Smith raped her at the Kennedy compound hours after she had met him, Senator Kennedy and his son, Patrick, at Au Bar, a Palm Beach nightspot.

Detectives should complete their investigation by the end of this month, Chief Terlizzese said.

The Palm Beach County Sheriff's office began tests yesterday comparing evidence taken from the alleged victim, including semen, with blood, hair and pubic hair samples that Mr. Smith gave to police over the weekend.

Palm Beach police spokesman Craig Gunkel said the lab tests on evidence taken from Mr. Smith and the woman may take as long as two weeks to be concluded. However, he said, an arrest could take place before that.

"If we feel we have enough probable cause to make an arrest, we'll make an arrest," he said. "We don't necessarily have to wait for test results."

A Palm Beach police detective traveled to Washington, D.C., over the weekend to take statements from Edward and Patrick Kennedy. Both have denied involvement in the alleged incident.

Chief Terlizzese, in an interview, suggested that police believed the two were not involved in the reported rape. "You don't take witness statements from suspects," he said.

Chief Terlizzese defended his department's investigation and said the case was being given no special treatment because the Kennedys were involved.

"Everything we do, we do it the same way," he said.

And, except for the media, the department has not felt any undue pressure, he said. Families of the Kennedys' stature, he said, are run of the mill in Palm Beach.

Meanwhile, in Washington, Senator Kennedy said he expected the police investigation to have no impact on his Senate duties but that it was taking a personal toll on him and his family, which was why he wanted the investigation wrapped up quickly, the Associated Press reported.

"It's obviously been a troublesome time," Senator Kennedy said, as Congress returned from an Easter recess. "But that's why I hope we get all the facts out. And I'm satisfied when they are that this will have a different connotation."

Because of what was reported as a scheduling conflict, Senator Kennedy did not attend a Senate Judiciary Committee hearing on legislation proposed by committee Chairman Joseph R. Biden Jr., D-Del., that would classify rape as a hate crime, the Associated Press reported.